Sewer-backwater safety valve



Feb. 10, 1931. G, HlZsA 1,792,091 v SEWER BACKWATER SAFETY VALVE Filed Feb. 26, 1930 JNVENTOR. Geza fzzzsa ATTORNEY Patented Feb. 10, `1931 (UNITED STATES 4Garzah nrzsA, org-ELIZABETH, NEW-JERSEY n .SEWER-Backwaren SAFETY VALVE y Application 'mea rem-nary 2e; ieeaser'ial No. 431,367.

' rlhis invention relates to new and useful improvements in `asewer backwater safety valve. f p

The invention has for an object the pro-V vision ofa device of the class mentioned whichis of `simple vdurable construction, de-

lpendable in use and efficient in action, and which can be manufactured and sold at a reasonable cost. A "The invention proposes a perforated disc for attachment on a sewer pipe or trap and provided with a shell onk its bottom side enclosing said perforationsand lterminating at the bottom" in a valve seat, a: stem slidable thru said ldisc coaxial with the axis of said valve seat', a valve head attached on said stem for engaging said valveseat and of inverted cup shape to entrap air and be buoyant on rising water, and means for limiting downward motion of said stem to determine the normal open position of saidvalve.

It is conventional to providefloatingrubber or metallic ballvalves'in sewer backwater safety valves which are held and guided at their extreme outer'surfaces on projections from the valve seat member. The instant invention distinguishes from this construction in the valve head which is of a4 design making the entire device more efficient and more sensitive to the iiuctuations of the sewerV backwater pressure. This is particularly so for valves of the same sizes.

The inverted cup shaped -or bell shaped valveV head necessarily has a large-bottom opening for cupping upon the surfacev of rising water. Further, it has a substantial cubical volume for entrapping a large quantity of air which'may be slightly compressed for the purpose hereinafter fully stated. The design of the valve head adds agility Vto its operationso thatlit opens and closes very rapidly, preventing escape of sewer waterinto y a cellar or basement." The invention also proposes means for urging the valve into good sitting position on said valve seat upon the ,closing of the valve. l

For further comprehension of the invention, and of the objects and advantages thereof, reference will be had to the following description and accompanyingdrawings and the to the appended claims in which the various novel lfeatures of the invention are more particularly 'set' forth.

'In the accompanying drawing forming a material part of this disclosure Fig. 1 is a plan view of a device constructed according to this invention.

Fig. 2 is a side elevational view of Figgl.

Fig'. 3 is a vertical sectional view taken on the line 3-3 of Fig. 1.

y Fig. 4 is an enlarged fragmentary view of a portionv of Fig. V3. Y

. The sewer backwater safety valve consists of a perforated disc 10 for attachment on a sewer pipe or trap and provided with a shell portion 11 on its bottom side 12 enclosing the perfo-rations of said disc and terminating at the bottoni ina valve seat 13, a stem laslidable thru said disc 10 coaxial with the axis of said valve seat 13, a valve head 15 attached on said stem 14 for engaging upon said seat 13 and `of inverted cup shape to entrap air and be `buoyant on risingwater, and means for limiting the downward motion of said stem to `determine the normally opened position-of vsaid valve. l

The perforations on the disc 10 are indicated by reference numeral 16'and are circular and countersunk at the tops; The attachment of the perforated disc upon a sewer pipe ortrap -may be. accomplished with threads 17 externally arranged upon the shell 11. A hexagonal portion 18 projects fromA the top of the disc 10 for engagement with a wrench or other tool so as to screw the device in place. ing'of the perforations 16 so that all water passing' thru these perforations must pass the valve seat 13. A boss 19 is formed upon the bottom of the disc 12 and an aperture 20 is formed vthru the -boss 19, the disc 10 and the 'hexagonalportion 18 Ifor the reception of the vstem 14; and constituting the slidable arrangement of the stem. i

A* screw' 21 engages thru the valve head 15 and into theibottom of the stem 14 and accomplishes the securing together of these parts. The inverted cup shaped valve head 15 has a large diameter bottom opening 22 for cupping upon rising water. Further, its cubical vol- The shell accomplishes an inclosiii ume is relatively large as compared with a sphere made of the same mass and same thickness of material. The means for limiting downward motion of the stem to determine the normally opened position of the valve consists of a pair of nuts 24 threadedly engaged upon the top of the stem and abuttable against the projection 18. A portion of the projection 18 is formed'with threads 25 so Jthat a cap 2G may be` threadedly engaged thereon and cover the top of the stem 14 and the nuts This cap is formed with a knurled portion 27 for manual clipping in its removal, and with a top aperture 2S for ventilation. Y

In operation of the device, water from the exterior may flow thru the perforated disc and past the valve seat 13 into the sewer or other discharge pipe. ln the event that the water from the sewer backs up, it engages against the bottom of the valve head A15 entraviping air within the valve head causing it to be buoyant and rise for engaging against the seat 13 and cutting oli' the passage of the water up thru the perforations 16 and into the basement, cellar or other place. After the water has receded, the valve head `15 falls under the action of gravity so that water may run down into the sewer. rl`he nuts 24 may be adjusted for regulating the amount to which the valve head 15 moves from its seat.

1n Fig. il, a portion of Fig. 3 has been enlarged to clearly show a. means for urging the valve 15 into good sitting position upon the valve seat 13 upon closing of the valve. This means consists ofstem sections and 31 constituting the stem 14; and threadedly engaging each other so that upon being forced together to move apart to slightly turn relative to each other. A pin 32 projects from one of the stem sections and engages in an opening in the other stem section for limiting the separating' of these parts. An expansion spring acts between the stein sections for normally urging them into spread positions.

A protuberance 35 projects from the top stem section and is engageable against the boss 19 on the bottom of the disc 10 for limiting the upward motion of the top stem section. The bottom stem section 31 is attached upon a metallic diaphragm 3G attached upon the closing and opening in thevtop of the valve head 15. lVhen the valve head rises under the upward motion of rising water, it engages against the valve seat 13 for preventing backllow of the sewer. Continued rising of the water within the sewer compresses the air within the valve head 15 so that the dia.- phragm 36 moves upwards causing the. valve stem section 31 to move closer to the stem section 30 and therefore turn relative thereto so that the valve head turns upon t-he valve seat 13 and away or assumes a better sitting position.

While I have shown and described the preferred embodiment of my invention, it is to be understood that I do not limit myself to the precise construction herein disclosed Vand the right is reserved to all changes and modifications coming within the scope of the invention as defined in the appended claims.

Having thus described my invention, what l claire as ynen/,and desire to secure by United States Letters Patent is 1. A sewer backwater safety valve, comprising a perforated disc for attachment on a sewer pipe or trap and provided with a shell on its bottom side enclosing said perforations and terminating at the bottom in a valve seat, a stem slidable thru said disc coaxial with the axis of said valve seat, a valve head attached on said stem for engaging said valve seat and of inverted cup shape to trap air and be buoyant on rising water, means `for limiting the downward motion of said stem to determine the normally opened positionof said valve, and means for urging the valve into good sitting position on said valve seat upon closing of the valve, comprising stem sections constituting said stem and threadedly engaged with each other so that upon slight longitudinal movements to slightly rotate relative to each other, and means for limiting the relative movements of the stem sections, means for normally urging the stem sections apart, and a metal diaphragm engaged over an opening in said valve head and connected with the bottom of vsaid stem sections. i

2. A sewer backwater safety valve, comprising a perforated dise for attachmenton a sewer pipe or trap and provided with a shell on its bottom side enclosing said perforations andterminating at the bottom in a valve seat, a stem slidable thru said disc coaxial with the axis `of said valve seat, a. valve head attached on said stem for engaging said valve seat and of inverted cup shape to trap air and be buoyant on rising water, means for limiting the downward motion vof said stem to determine the normally opened position of said valve, and means for urging the valve into good sitting position on said valve seat upon closing of the valve, comprising stem sections constituting saidstem and threadedly engaged with each other so that upon slight longitudinal movements to slightly rotate relative to each other, and means Afor limiting the relative movements of the stem sections, an expansion Aspring for normally urging 'the stem sections apart, and a metal diaphragm engaged over an opening in said valve head and connected with the bottom of said stem sections.

3. A lsewer backwater safety valve, comprising a perforated disc for attachment on a sewer pipe or trap and provided with a shell on its bottom side enclosing said perforations and terminating at the bottom in a valve seat, a stem slidable thru said disc coaxial with the axis of said valve seat, a valve headl attached on said stem for engaging said valve seat and of inverted cup shape to trap air and be buoyant on rising water, means Jfor limiting .the downward motion of said stem to determine ythe normally opened position of said valve,

and means for urging the valve into good sitting position on said valve seat upon closing v diaphragm engaged over an opening in said ofthe valve, comprising ste-m sections constituting said stem and threadedly engaged with each other so that upon slight longitu dinal movements to slightly rotate relative to f each other, and means for limiting the relavalve head and connected with the bottom of said stem sections.

In testimony whereof I have affixed my signature.

GEZA HIZSA. 

